Can't vouge for Mountain Horse boots, but I'll take everybody's word on them. =D I kick myself, however, for wearing out TOO MANY good, comfortable leather riding boots for chores!!!!
I love 100% wool socks. However, in my 26 horse-chore filled winters, I find that they wear through the toes and the heels. =(
My alternative is to use the least expensive wool socks, which I've found are carried at Farm & Fleet (midwest chain, but check you local farm supply stores.) They currently run $3.99/pair, come in olive and navy, and they're 85% wool, 15% nylon. The nylon (rayon, maybe?) is in the elastic at the top of the socks. They are slim enough to fit into your existing boots, but are also toasty. They also wear MUCH better in the toes and heels. Another inexpensive alternative is to layer these
with 100% cotton (tube) socks on the outside of the wool ones. HowEVER you sock up, you need boots that are roomy enough for you to move your toes. You need a pocket of air in your boots so that the heat from your feet will be trapped. Otherwise your stiff toes WILL get cold. BELIEVE me, I've tried EVERYTHING bc it's always been just me feeding/caring for my horses in the wet, the cold, and the blizzards!!
Regarding your outerwear, layer, layer, layer! If you're in the market for a new coat buy one size larger and make sure it's really roomy. The best underwear IMHO is 2-piece silk. It's very lightweight and much warmer, imo than any synthetic.
I have a collection of winter-wear, and all-year chore wear in a cabinet in my basement (by the steps and door to the back.) I prefer to start with a long-sleeved undershirt first, then a t-shirt, then a sweater and I like sleeveless down vests on top. I like only one pair of long underwear pants under my riding pants. I also have 2 pairs of wool-flannel-lined jeans, again to be found now at farm supply stores. Don't forget to buy a gator, or maybe one of these which I have~ Silk Clearance: Accessories at discounted prices
...but this would easily fit under your helmet~ Silk Warmth Headquarters: long underwear, accessories, outerwear, and more
Here is a page from the Winter Silks site that might help you. Silk Warmth Headquarters: long underwear, accessories, outerwear, and more
Frankly, if it's too cold to ride in these, I'd rather not! lol
ALMOST forgot--coat your face with your favorite lotion to keep it from drying out!! I use petroleum jelly, but some people are allergic to it. If you are not, I recommend it bc it's very affordable. Happy winter riding, all!!